Device for controlling ice formations



.June26, 1951. N M, LSEYFFERT 2,558,063

DEVICE FOR CONTROLLING I CE FORMATION Filed Aug. 13, 1945 /IV Men/r0 2.-MnRv/n/ L. 56 YFFERI;

Patented June 26, 1951 DEVICE FOR CONTROLLING ICE FORMATION S Marvin L.Scyflcrt, Clayton, Mo., assignor, by

Misso mesne assignments,

uri Automatic Control Corporation, a corporation of Missouri ApplicationAugust 13, 1945, Serial No. 610,559

This invention pertains to control devices generally and concerns itselfmore particularly with apparatus for controlling the volumetric degreeto which a change in state of a given medium is carried out.

It'is a general aim of the invention to provide a control circuit bymeans of which the degree to which a change in state of a given medium'is effected may be controlled, as, for example, water to ice.

It is a further object of the invention to provide a control circuitcapable of controlling the degree of a change of state of a givenmedium, said control circuit utilizing the resistive characteristics ofthe medium in its changed state.

Still another object of the invention is to provide apparatus forcontrolling the degree to which a change of state of a given medium iseffected by utilizing a portion of the medium in its changed state as anelectrode insulator.

More specifically, it is an object of the invention to provide a controldevice for water coolers refrigerated, by means of a refrigerating coilwhich will provide for an accumulation of ice on said coil to apredetermined amount.

Other objects and advantages will become apparent as the descriptionproceeds, and a more comprehensive understanding of the invention willbe afforded from the following detailed description, when considered inconjunction with the accompanying drawing, in which the figure is aschematic circuit diagram of a control device embodying the instantinvention.

While the instant invention is not limited to any particular use, itwill be described in connection with a beverage cooler unit, it beingspecifically understood that the invention is not to be limited to thisadaptation.

With reference to the figure, a tank II is illustrated as taking theform of a beverage cooler in which is carried a refrigerating coil l2supplied with a coolant by a refrigerating sys-I tem I3. The latterelement may take any of the usual forms and is thought of as comprisinga motor-controlled compressor which is turned on and off in accordancewith demands for refrigeration by means of a relay device M.

In the particular application here illustrated, the tank II is usuallyfilled with a cooling medium, such as water, and it is frequentlydesirable to havethe coil 12 coated with a certain amount of ice whichwill aid in carrying the cooling load imposed by the water in the tank.which is used to-cool immersed articles 13 Claims. (01.62-7) coolant tothe coil I2 to freeze the water in the tank, it isoften desirable tocontrol the amount of ice which is to be formed on the coil l2. For thepurpose of effecting such control, the instant invention is adaptable.

Here the refrigerating mechanism I3, which in other applications maytake the form of any device to be controlled, is operated by the relayl4 under thecontrol of an electronic switching element l5, which maytake the form of a tetrode. 'A control current is supplied to theelectronic discharge device 15 by means of a transformer l6 which hasits primary winding I! connected across a suitable source of electricsupply. The discharge device l5 has a cathode l8, a control grid IS, asuppressor 20, and a plate 2|. The cathode l8 and the plate 2! areconnected across a secondary winding 22 of the transformer l6 and are inseries with a relay winding 23, forming a part of the relay device eter28 is connected to the control grid I9 of the device l5. The circuit isgrounded at points 32 and 33 by means of a line 34. Also, a line 35 istied to the control grid I9 and connects with an electrode 36 mounted tobe in proximity to the coil [2 and insulated therefrom. The electrode 36is carried in a bracket 31 which is connected by aninsulating connectionto the coil l2 and is so arranged on a screw 38 as to be moved or awayfrom the coil l2.

With the parts arranged as shown, the screw 38 should be made ofnonconducting material. Also, that portion of the wire 35 extending intothe tank should be protected with Waterproof insulation so that only theelectrode 36 can make electricalcontact with the water in the tank.Thus, the setting of the electrode with respect to the coil I2determinesthe amount of ice which will form on the coil, since envelopment of theelectrode 36, only, is necessary to shut off the refrigerating system.

toward device co nducting-.' Dur ing the time this adjustmentds made, nowater is present in the tank. After it is made, the tank is filled withwater to immerse the coil and provide a cooling medium for the bottledbeverages. When the aforementioned adjustment s made, the shunt circuit,traceable from the point 33 through the line 34, the ground 39, the tankll,

the electrode 36, and the line 35 back to point 33,

is open between the electrode 36 and the tank Ii, since no water ispresent in the tank. When.

water is introduced into the tank, its relatively high conductivity (inits liquid state) closes the circuit from the electrode 36 to the tank,which effectively shunts out the left-hand portion of the potentiometerwinding 29 (to the left of the divider arm 3|). With the left section ofthe potentiometer thus shunted, the potential drop across that sectionis reduced, and the voltage appearing on the grid [9 is decreased. Thiscauses the discharge device I5 to be conductive, which, in turn,energizes the relay M to start the refrigerating system [3. This, inturn, supplies a coolant to the coil i2 and thereafter a coating of iceis formed on the coil. When this coating of ice has reached suiiicientproportions to envelop the electrode 36, the high resistive propertiesof the ice coating the electrode 36 efiectively insulate the same toagain open the shunt circuit previously described. With this branch ofthe circuit open. all of the winding 29 of the potentiometer 28 is madeoperative in the control voltage circuit causing a resultant increase inthe potential of the control voltage appearing on the grid 19, whereuponthe discharge device I5 is rendered nonconductive, and relay i4operative to shut off the refrigerating system 13. Thereafter, thesystem remains static until the ice melts from the electrode 36,whereupon the cycle is repeated.

It will be seen from the foregoing that a coating of ice is maintainedon the coil l2, whose volumetric proportions are determined by theposition of the electrode 36 with respect to the coil i2. Since theelectrode 36 is adjustable relative to the coil by means of the screw38, it is possible to maintain a coating of ice on the coil l2suflicient to aid in carrying the ooling load as determined by variableconditions.

While a particular embodiment of the invention has been illustrated anddescribed, it is apparent that many wide variations and changes could bemade therein. Accordingly, all such changes and modifications to whichthe invention is susceptible are included as if described, and theinvention is to be limited only by the appended claims.

What is claimed is:

1. In a device of the class described, electrically operable means forchanging water toice, a source of power,control means for saidelectrically operable device including a circuit connected through thewater to be frozen and operative upon the flow of current through thewater to render said electrically operable means operative, and upon thedecrease in current flow through the water when the same is frozen torender said electrically operable means inoperative.

2. In a device of the class described, 'a cooling 4 medium, electricallyoperable means for changing said medium from a first state havingrelatively high conductivity to a second state having relatively lowconductivity, a source of power, an operating circuit for saidelectrically operable means, a switch in said circuit, said switch auto-..matically moving to an open circuit position when released, and meansfor controlling said switch including a control circuit connectedthrough said medium, said means being rendered operative to close saidswitch and hold it closed in response to the flow of current throughsaid medium in said first state and rendered inoperative upon thereduction of the flow of current through said medium in said secondstate.

3. Ina refrigerator having in combination a refrigerant, electricallyoperable means for causing a change from a liquid to a solid state insaid refrigerant, and means for controlling the operation of saidelectrically operable means including a source of power, a circuitconnected through said refrigerant and means connected in said circuitand responsive to the flow of current through said refrigerant when saidrefrigerant is in said liquid state to render said electrically operablemeans operative and responsive upon the reduction in the flow of currentthrough said refrigerant when changed to said solid state to render saidelectrically operable means inoperative.

4. In a control device for use with a refrigerating system having arefrigerating coil immersed in a freezable medium, and means forsupplying a coolant to the coil, means for controlling saidrefrigerating system to maintain a coating of the medium in frozen stateon said coil, comprising a relay switch for turning said refrigeratingsystem on and oif, a circuit therefor, the circuit including a portionof said medium and utilizing a change in the electrical properties ofsaid medium due to a change in its state from liquid to solid, and thecoating of a predetermined thickness ofthe medium on the coil forcontrolling the operation of said relay switch.

5. In combination with a water cooling device having a refrigeratingsystem for supplying a coolant to a coil immersed in the water to becooled, means for controllin said refrigerating system to maintain acoating of ice on said coil to a predetermined amount comprising anelectrically operated switch, electronic switching means for operatingsaid switch, and means responsive to changes in the electricalproperties of said water in changing from its liquid to solid state forcontrolling the operation of said electronic switching means.

6. In combination with a water cooling device having a refrigerating.system for supplying a coolant to a coil immersed in the water to becooled, means for controlling said refrigerating system to maintain acoating of ice on said coil to a predetermined amount comprising aswitch for turning said system on and oii, a relay for operating saidswitch, circuit means for energizing said relay, an electronic dischargedevice connected in said circuit means havin a control element andoperative to energize said circuit means, means for impressing a controlvoltage on said control element including a resistance, and an electrodemeans connected to said control voltage impressing means and mounted inproximity to said coil whereby the same is positioned to be enveloped byice formed on said coil to shunt out a portion of said resistance.

7. Apparatus as claimed in claim 6 including means for adjusting theposition of said electrode means relative to said coil.

8. In a method of producing a predetermined amount of ice adjacent anice machine in a body of freezable liquid, the steps of operating themachine to produce ice in progressively increasing thickness outwardlyfrom the machine, selectin two datum points between which the iceprogressively forms, including the two points in an electrical controlcircuit, applying a potential between the two points, obtaining apotential drop between the points that increases progressively as theice forms, and employing said potential drop to regulate the machine andcause it to stop when a predetermined portion of the linear distancebetween the points is ice.

9 In combination, a member subject to accumulation of ice thereon inincreasing thickness, an electric circuit including two terminals spacedby a gap in which the ice accumulates, operated means in the electricalcircuit operable to control the formation of the ice, the ice being acomponent of the electrical circuit and controllining the current flowtherein, the circuit being conductive when the ice formation betweenelectrodes is below a predetermined thickness, and becoming lessconductive as the thickness increases, and means responsive to theamount of conductivity of the circuit to determine operation of theoperated means, whereby when the ice has a predetermined thickness thecircuit will be energized to operate the operated means.

10. In combination, a member subject to accumulation of ice thereon inincreasing thickness, an electrode spaced from the member by a gap,

and constituting a first terminal, a second terminal spaced from theelectrode, an electrical circuit including the two terminals one ofwhich is the electrode, and the two terminals being connected throughthe accumulating ice, the circuit including also an operated meansenergizable to control the thickness of the ice, and includingconnections for a source of electrical energy, the circuit beingenergized when the ice in the gap has only a predetermined thickness,whereby the operation of the operated means is determined by thethickness of the ice.

11. In combination, a member on which ige accumulates, operable means tocontrol the amount of ice produced, a pair of electrical terminalsspaced by a gap, the ice accumulating on one of the terminals, anelectrical circuit including the operable means, the two terminals, andconnections for electrical power, the amount of ice on the electrodechanging the electrical characteristics of the gap and hence of thecircuit, whereby the operable means is energized when a predeterminedamount of ice is present in the gap.

12. In a method of regulating production of frozen liquid outside thecoil of an ice machine, from a mass of freezable but unfrozen matterfrozen, rendering a control mechanism respon sive to a particular valueof the electrical characteristics that represents a predetermined amountof frozen. liquid between the datum points, and operating the mechanismby said control.

13. In a method of regulating production of frozen liquid outside thecoil of an ice machine,

from a mass of freezable but unfrozen material, by a change-of-statemechanism, the matter havin 'difierent electrical characteristics in itsunfrozen state from those in its frozen state, the steps of operatingthe mechanism, obtaining datum points between which the matter willprogressively change state and change the ratio of matter in its firststate to matter in its second state, including said points in anelectrical control circuit for the mechanism, to put the matter beingchanged in state, in the control circuit, applying a potential to thecircuit, obtaining a potential drop across the matter that is a functionof the amount of matter that is frozen, and varies with the amount ofmatter that is frozen, and re mring the control circuit responsive to aparticular potential drop that is representative of a particular amountof frozen matter between the datum points, so as to render the mechanism operative and inoperative when the potential drop reaches apredetermined amount.

MARVIN L. SEYFFERT.

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